This capsule, number 15B, is the only one left showing the complete one-man spacecraft in its orbital configuration. It includes the silver and black retrorocket package used to slow the capsule for return to Earth, and the nose section containing the parachutes.

The capsule was originally sent to Cape Canaveral in 1961 for a manned suborbital mission, Mercury-Redstone 5 (MR-5) that was cancelled. It was then modified for an orbital mission and renumbered 15A, and then modified again as a backup to the Mercury-Atlas 9 (MA-9) spacecraft, and again reassigned as the prime spacecraft for the MA-10 mission and renumbered to capsule 15B.

The MA-10 mission would have flown Alan B. Shepard, Jr. (the first American in space) in a long-duration orbital mission in late 1963. Shepard had the name Freedom 7 II (in tribute to his historic 1961 capsule, Freedom 7) painted on the spacecraft. But after the success of MA-9 in May of that year, NASA decided to cancel MA-10 to concentrate on its next human spaceflight project, Gemini.